Electric-arc lamp.



PATENTED AUG. 25, 1903.

H. T. HARRISON. ELECTRIC ARC LAMP.

APPLIOATION FILED JUNE 27. 1902.

2 SHEETSSHEET 1 N0 MODEL.

Jaw/WW EN 70H.

WITNESSES:

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PATENTED AUG. 25, 1903.

H. T. HARRISON.

ELECTRIC ARC LAMP.

APPLICATION FILED JUNE 27 2 SHEETS-SHEET 2.

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UNITED STATES Patented August 25, 1903.

PATENT OFFICE.

IMPROVED ELECTRIC GLOW LAMP ENGLAND COMPANY, LIMITED, or LONDON,

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 736,966, dated August 25, 1903.

Application filed June 27, 1902. Serial No. 113,452. (No model.)

To all whom it may concern.-

Be it known that I, HAYDN THIES HARRI- SON, a subject of the King of Great Britain and Ireland, residing at London, England, have invented a new and useful Improvement in Arc-Lamps, (for which I have made application for Letters Patent in Great Britain under No. 3,157 and date February 7, 1902,) of which the following is a specification.

This invention relates to that type of lamp in which the arc burns in a practically airtight globe and in which the continuation of the lower-carbon holder is immersed partially in mercury and is operated by an external solenoid; and my improvement consists in an attachment for supporting the said lower-carbon holder by buoyancy in the said mercury, which attachment shall always be totally immersed, so that it can be adjusted by movable Weights to a normal position of actual flotation of sensitive equilibrium or so that it shall sink, as may be desired, and so that the said upward force acting contrary to gravity shall remain practically constant for all positions of the carbon-holder, and in the arrangements of solenoid circuits and cores to suit the said conditions of the holder, and in the arrangement of the said holder and attachment so that its movements, which are rendered very sensitive, shall be eflectually retarded or damped whether moving up or down.

Figure l is a sectional elevation of the lamp with shunt-wound coil. Fig. 2 is a sectional detached detail of lower mercury-receptacle and lower-carbon holder with series- Wound coil. Fig. 3 is a similar sectional detached detail With compound-wound coils. Fig. 4 is a sectional and outside elevation as a detached enlarged detail of the lower-carbon holder, core-float, and damping device.

The lower part of the type of lamp referred to is a metallic tube or receptacle 1, containing mercury, such tube being connected in any suitable manner to an air-tight globe 2 and to a fixed insulated upper-carbon holder 3,which are not further particularly described,

as they form no part of the present improvement.

The lower movable carbon requiring sensitive adjustment is mounted in a holder 4, having a flange 5, adapted to receive adjusting washer-weights 6. The holder 4 is connected by a metallic stem 7, passing through a bush 8 to a tube 9, to which iron cores 10 may be attached or which itself may be an iron core.

To the lower part of the tube 9 I attach a float 11, of solid material lighter than mercury, or constructed partially hollow insuch a manner that it serves to give a definite buoyancy pressure in excess of the whole weight of the lower-carbon holder, connections, and carbon. Such float 11 being at the bottom of tube 9 is always completely immersed in the mercury Whatever the position of the lower-carbon holder, and the mercury has also access to the interior of the tube 9 by an aperture or channel through the float 11, which channel is hereinafter more fully described. Thus the buoyancy of immersion does not in my improved construction vary practically at various positions of the lowercarbon holder, the tube 9 and cores being of very slight section and the mass of the float giving the necessary buoyancy by displacement and being always fully immersed renders such displacement and buoyancy always practically constant.

I may utilize the tube 9 as an iron core with a truncated conicity in the direction of its entry into a surrounding regulating solenoidcoil12, as in Fig. 1, or I may apply thin sheetiron wedge-strips 10 on several sides to such parallel tube 9 of non-magnetic material, as shown in Figs. 2, 3, and l, the breadth of the strips being narrowed in the direction of their entry into their respective solenoids, obtaining thus by the uniform proximity of the core to the solenoid-coil throughout with a In order to damp sufficiently the movement of the lower carbon either up or down to prevent over-running or vibration of the lower carbon during its movement, I find that a simple hole forming communication between the exterior mercury and the interior of the tube 9 is not adequate, and I therefore provide a hole or channel 13 of considerable length through the body of the float 11, which has also several sharp-angled bends in its course. (See Fig. 4.) Such form of channel owing to the inertia and comparative viscosity of the mercury and to the long frictional surface of the channel aifords a considerable retardation to the passage of mercury through it, and thus to the movement of the float through the mercury.

To adapt my improved lamp to various conditions of winding when the lamp is shuntwound, I apply the solenoid-coil 12 to the upper part of the lower mercury-tube 1,connecting the said coil in shunt to the main circuit through the carbons, as shown by the line-and-dot circuits in Fig. 1, and I so weight the lower-carbon holder by weight-washers 6 on the flange 5 of the lower carbon that its.

original buoyancy of floatation is overcome and its normal position when no current is passing is at its lowest point, and the tendency of' the coil when excited is to lift the holder.

When the lamp is series wound, the lowercarbon holder and attachments are adjusted to normally have a margin of buoyancy, the solenoid-coil l2 being fixed about the lower part of the tube 9 and connected in series in the lamp-circuit,as shown in Fig. 2, and when excited it has the tendency to draw the holder down.

When the lamp is compound wound-that is, with two adjusting-coils, one in shunt and the other in series with the arc-current-the lower-carbon holder and attachments are adjusted to be actually in equilibrium of floatations, the wedge-cores 10 on the tube 9 being duplicated from the center. The shunt-coil 12 is at the top of thetube 9 and series coil 12 at the bottom, the coils being connected to the arc-current, as shown in Fig. 3.

Having now described my invention, what I claim, and desire to secure by Letters Patent, is

1. In an electric-arc lamp, in combination, a depending tube receptacle for the lowercarbon holder; a volume of mercury therein; a tube continuation of the carbon-holder within said tube receptacle, adapted as a metallic core to a surrounding solenoid; a float attachment to the bottom of said tube-core, adapted by position to be always immersed in said mercury; a channel of communication through the substance of the float between the external bath of mercury and the interior of the tube-core; and a solenoid surrounding said tube receptacle, suitably connected to the arc-circuit.

2. In an electric-arc lamp,in combination, a depending tube receptacle for the lowercarbon holder; a volume of mercury therein; aparallel tube continuation, of non-magnetic material, of the carbon-holder, within said tube receptacle; wedge-shaped strips of iron, affixed to various sides of said continuationtube, adapting it as a metallic core,with uniform proximityand diminishing metallic surface, to the surrounding solenoid; a float attachment to bottom of said core; a channel of communication between external bath of mercury and the interior of the tube-core; and a solenoid surrounding said tube receptacle, suitably connected to arc-circuit.

3. In an electric-arc lamp, in combination, a depending tube receptacle for the lowercarbon holder; avolume of mercury therein; a tube continuation of the carbon-holder within said tube receptacle, adapted as a metallic core to a surrounding solenoid; a float attachment to bottom of said core, situated, relatively to the level of mercury, so that it is always completely immersed therein; a lengthy zigzag channel of communication, having a number of sharp-angled bends in its course, between the external bath of mercury and the interior of the tube-core; and a solenoid, surrounding said tube receptacle, suitably connected to the arc-circuit.

4. In an electric-arc lamp, in combination, a depending tube receptacle for the lowercarbon holder; a volume of mercury therein; a tube continuation of the carbon-holder within said tube receptacle, adapted as a metallic core to a surrounding solenoid; a float attachment to bottom of said tube-core, adapted to be always completely immersed, and of such density and displacement as to give absolute flotation by buoyancy to the lower carbon, its holder, and attachments; a channel of communication between external bath of mercury and the interior of the tube-core; and a solenoid surrounding the bottom of the said tube receptacle connected in series with the arc-current.

5. In an electric-arc lamp, in combination, a depending tube receptacle for the lowercarbon holder; a volume of mercury therein; a tube continuation of the carbon-holder within said tube receptacle, adapted as a double metallic core to the surrounding solenoids; a float attachment to bottom of said tube-core, adapted to be always completely immersed, and, as to its density and displacement, to

give absolute flotation by buoyancy to the carbon, its holder, and attachments; adj usting-weights upon the said carbon-holder,- to give definite equilibrium of flotation to the carbon-holder and core; and two solenoids,

one wound in shunt, and the other'in series adapted to act as a retarding-channel for the IQ with the arc-current, surrounding the said passage of liquid therethrough.

tube receptacle. In witness whereof I have hereunto set my 6. In an electric-arc lamp of the type rehand in presence of two witnesses. 5 ferred to, the combination with a loWer-car- HAYDN THIES HARRISON bon holder having a tube continuation and a float attachment thereto; of a lengthy and Witnesses:

zigzag channel through said float, with sev- RICHARD AQHOFFMANN, eral sharp-angled bends in said channel, 1 CHARLES CARTER. 

